Consider merging https://chromium.googlesource.com/chromium/blink/+/3d1744e53a3540be9bdb385deadec60469e6019c
or come up with a similar improvement
This is about +2% on Parser/css-parser-yui.html locally.
Previously, we were allocating and freeing small vector buffers (most commonly
24 or 72 byte allocations on 64-bit), only to immediately throw them away.
Note that uncheckedAppend has an ASSERT that will cleanly catch any future
problems with sizing.
Still worth taking? Seems like a pretty small change, but might be out of date now.
I don't believe this is still needed after:
*** This bug has been marked as a duplicate of bug 140599 ***